Wrench of the pivoted jaw type



May 25, 1965 o. A. CAPRA WRENCH OF THE PIVOTED JAW TYPE Filed NOV. 20, 1962 mvwroa I O T TH we 5. CHPRFI B g JJ mmm H T TOR NE 7 United States Patent 3,184399 WRENCH OF THE PTVGTED HAW TYPE Gttavio A. Capra, 152-44 84th Drive, Jamaica, NY. Fiied Nov. 20, 1%2, Ser. No. 253,936 6 Claims. c1. 81-401 The invention relates to a wrench of the type with a pivoted jaw which simplifies the construction without reduction in effectiveness and efficiency of the wrench. Although the construction is applicable to wrenches made out of various metals, the wrench particularly illustrated is intended to be made of metals which will not spark, including a handle and frame of aluminum alloy for lightness.

It is an object of the invention to construct a wrench of the type with a pivoted jaw which is simplified in construction, hence can be made at a favorable cost, and yet has full efliciency to grip a pipe.

Another object is to utilize a spring of convex shape to propel the pivotal or hook jaw of the wrench with increasing leverage as the hook jaw pivots away from the handle jaw.

Another object is to construct a wrench with convex gripping jaws for assuring centering of the jaws on a work piece and maximum jaw pressure at the center of the jaws.

A still further object is to lighten the weight of the wrench by making the major part including the handle and frame of aluminum alloy with a rectangular cross section for strength and longitudinally hollow for reduced weight.

Another object is to provide a wear plate between the nut and the aluminum handle frame and to provide an inexpensive part which is easily replaceable when worn.

Other objects of the invention will be more apparent from the following description when taken in connection with the accompanying drawings illustrating a preferred embodiment thereof, in which FIG. 1 is a side view of the wrench;

FIG. 2 is a front view of the wrench;

FIG. 3 is a cross section through the wrench of FIG. 1 taken on line 33;

FIG. 4 is a plan view of the wear plates;

FIG. 5 is a plan view of the convex spring;

FIG. 6 is a plan view of the convex spring;

FIG. 7 is a partial view showing the spring compressed.

The wrench includes a combined handle with frame means 10 including a handle and an integral frame 12, preferably made of aluminum alloy for lightness, and the handle being of rectangular cross section for strength. A longitudinal hole 11 of rectangular cross section extends through the handle to further increase the lightness of the handle and frame means. The handle has an axis extending longitudinally. The frame 12 which is integral with the handle is located at or adjacent one end of the handle. This frame has a nut aperture 13 extending laterally through the frame. The frame also has a longitudinally extending hole 14 therethrough having straight sides 15 and one end surface 16 tapering outwardly from the nut aperture to allow-freedom for pivoting a hook jaw. The nut aperture surface is also tapered at least for the upper surface 17 thereof with this surface tapering upwardly about 5 with respect to a line normal to the axis of the handle. Preferably too the lower surface 18 of the nut aperture tapers downwardly about 2 from a line normal to the handle axis so that the combined taper of the top and bottom surfaces of the nut aperture taper with respect to each other by about 7.

With a handle of aluminum, which is relatively soft, a handle jaw 21 of hard material is used which is insertable in position on the upper end of the handle. It

3,l84,99 Patented May 25, 1965 "ice may be secured thereto in any suitable manner, the securing means illustrated including a tongue 22 extending downwardly therefrom and carrying an upwardly extending spring finger 23, which tongue and finger is pressed into the hole 11 in the handle and retained therein by the pressure of the spring finger 23.

A cooperating hook jaw 26 has a shank 27 integral therewith and carrying threads 28 for adjustment of the spacing between jaws. The shank is slidable in the longitudinal hole 14. A nut 31 is received in the nut aperture 13 and has threads to receive the threads 28 on the shank of the hook jaw. A convex spring 32 (FIG. 5) has a hole 33 therethrough to receive the shank 27. This spring is received below the nut and its ends engage the lower surface 18 of the nut aperture adjacent to the inner and outer ends of the nut aperture so that the convexity of the spring is from end to end of the aperture. Preferably the ends 34 of the spring are rounded or curled for smooth engagement with the bottom surface 18, when the spring flexes.

With an aluminum frame, it is desirable to provide a wear plate 37 (FIG. 4) which has a hole 38 therethrough to receive the shank 27 of the hook jaw. The frame and the wear plate comprise the frame means when a Wear plate is provided. The frame alone constitutes the frame means if a wear plate is not provided. This wear plate is provided between the nut and the upper surface 17 of the nut aperture.

The vertical dimensions of the nut aperture, nut and wear plate are such that the spring normally fits between the nut and the lower surface of the nut aperture without any or little pressure or deflection of the spring. The shank 27 and the hook jaw 26 pivot on the edge of the nut and on the corner surface 40 of the frame means, that is on the adjacent corner of the wear plate 37 if such wear plate is provided or on the frame if no Wear plate is provided and when so pivoted the spring exerts upward pressure on the nut. 'I he convex spring 32 provides a short leverage arm when the hook jaw is in releasing position, the point of contact between the spring and lower surface of the jaw being at the point 41 nearer the handle or pivot point 40. When the hook jaw is pivoted on the pivot joint or corner 40 for insertion of a pipe into the jaws of the wrench, the point of contact of the spring moves outwardly, as shown in FIG. 7 so that the point of contact of the spring with the nut, when fully flattened, is at contact point 42. In other words, the line of spring pressure parallel to the axis of the shank is nearer the pivot corner or surface 40 when the shank is in normal position and this spring pressure line on the nut moves farther away from the pivot when the shank pivots which lever arm increases to about 2 to 1. This is in addition to the increase in spring pressure caused by flattening or compression of the spring. This increasing lever arm increases the effectiveness of the spring when the hook jaw has been pivoted to full open position.

It has been mentioned hereinabove that the wrench is preferably of materials which are spark free or sparkless in that the hook jaw and its shank, the nut, the spring and the wear plate are all of beryllium copper. The jaw 21 is of beryllium nickel so that it may be hardened and drawn giving it a hardness of Rockwell-C, that is a 53-55 hardness. If desired, the wear plate 37 may also be of beryllium nickel and hardened for increased wear. This wear plate not only serves to prevent excessive wear of the relatively soft aluminum alloy frame 12, but it also provides an easily replaceable element, if and when this plate should become excessively worn.

The jaws are provided with convex surfaces 47 across 3 ml) the width of the jaws of large radius preferably of about 7 inches, With the center of the radius in alinement with the axis of the wrench. This centers the work piece or pipe between the jaws and assures that maximum pressure on the jaws is provided at the center of the shank.

and the center of the shank and the center axis of the handle. The radius may be larger or smaller over a wide range, however, the curvature should not be so small that essentially point contact is secured between the jaws and the work piece, since this would unduly concentrate jaw pressure on the latter.

The handle may have reinforcing flanges 45, extending along the back edges of the handle adjacent the frame and outwardly therefironnso that it also extends along the lower edge of the frame. Preferably too a second reinforcing flange 46 is provided on each side of the frameextending along the upper edge of the nut aperture 13 and on each side thereof.

This invention is presented to filla need for improve.

ments in a wrench of the type with a pivoted jaw. It is understood that various modifications in structure, as well as changes in mode of operation, assembly and mannor of use, may and often do occur to those skilled in the art, especially after benefiting from the teachings of the invention. This disclosure illustrates the preferred means of embodying the invention in useful form.

I claim:

1. A wrench comprising a handle having an axis, frame means projecting laterally from the handle at one end thereof including a frame, a jaw at the end of the handle, the frame having a nut aperture extending laterally through the frame, the upper surface of the nut aperture tapering upwardly at about 5 from a line normal to the handle axis, the frame having a longitudinally extending shank hole and connecting with the nut aperture and having at least the side thereof adjacent to the handle tapering outwardly toward the handle. fromthe nut aper-. tuzre, a hook jaw having a shank received in the shank hole, screw threads on the shank, a nut having screw threads engaging the screw threads on the shank and received. in the nut aperture, the edge of the nut engaging the inner corner of the frame means for pivoting ofthe shank and hook jaw relatively to the handle jaw, a spring of convex form having a hole therethrough for receiving the shank and positioned between the nut and the lower surface of the nut aperture, and the convexity of the spring being from inner wall to outerw'all of the nut aperture whereby the point of contact of the spring with the nut moves outwardly as the spring flattens to give 4 an increasing lever arm for the spring pressure on the nut.

2.. A wrench as in claim 1 in which the gripping surfaces of the jaws are convex laterally of the jaws and of relatively large radius and with the high point of the convexity being. centrally of the sides of the jaws.

3. A wrench as in claim 1 in which thenut aperture has a lower surface which tapers downwardly from a line normal to the axis of the handle at an angle of about 2 degrees.

4. A wrench as in claim 1 in which the handle and frame are of aluminum, the handle jaw being secured to the end of the handle, and the frame means including a wear plate of long wearing material engaging the ends of the nut aperture and having a hole therethrough for the shank of a size allowing free movement of the shank therein, and the wear plate being located between the nut and the upper surface of the nut aperture.

5. A Wrench as in claim 4 in which all other parts except the handle. are. of 'berylliumvalloy to provide a spark free wrench.

6. A wrench as in claim 4 including convex surfaces on the jaws extending laterally of the jaws andwith the high point of the convexitybeing centrally of the sides.

of the jaws for centralizing the work piece therebetween.

References Cited by theExaminer UNITED STATES PATENTS 440,564 11/90 'Hammond 8l98 728,881 5/03 Donaldson 81-101 937,562 10/09 Anderholm 81--101 1,143,350 6/15 Benedict 81-l01 2,063,318 12/36 Larson 8ll04 2,514,687 7/50 Werner 8l-111 2,585,090. 2/52 Carnelli 81-101 2,629,279 2/53 Smith-Petersen et al. 81-101 2,656,751 10/53 Johnson et al. 2,704,477 3/55 Wright s1 101 2,748,638 6/56 Walker 81-101 2,760,395 8/56 ;St. Pierre 81-101 2,766,650 10/56 Capra. 3,085,456 4/63v Laycockaet al. 81--l01 FOREEGN PATENTS 479,363 2/38 Great Britain.

WILLIAM FELDMAN, Primary Examiner- MILTON S. MEI-IR, Examiner. 

1. A WRENCH COMPRISING A HANDLE HAVING AN AXIS, FRAME MEANS PROJECTING LATERALLY FROM THE HANDLE AT ONE END THEREOF INCLUDING A FRAME, A JAW AT THE END OF THE HANDLE, THE FRAME HAVING A NUT APERTURE EXTENDING LATERALLY THROUGH THE FRAME, THE UPPER SURFACE OF THE NUT APERTURE TAPERING UPWARDLY AT ABOUT 5* FROM A LINE NORMAL TO THE HANDLE AXIS, THE FRAME HAVING A LONGITUDINALLY EXTENDING SHANK HOLE AND CONNECTING WITH THE NUT APERTURE AND HAVING AT LEAST THE SIDE THEREOF ADJACENT TO THE HANDLE TAPERING OUTWARDLY TOWARD THE HANDLE FROM THE NUT APERTURE, A HOOK JAW HAVING A SHANK RECEIVED IN THE SHANK HOLE, SCREW THREADS ON THE SHANK, A NUT HAVING SCREW THREADS ENGAGING THE SCREW THREADS ON THE SHANK AND RECEIVED IN THE NUT APERTURE, THE EDGE OF THE NUT ENGAGING THE INNER CORNER OF THE FRAME MEANS FOR PIVOTING OF THE SHANK AND HOOK JAW RELATIVELY TO THE HANDLE JAW, A SPRING OF CONVES FORM HAVING A HOLE THERETHROUGH FOR RECEIVING 